Steam generating apparatus



Oct. 17, 1933. K BAUM 1,931,426

STEAM GENERAT ING APPARATUS Filed Oct. 18, 1930 2 Sheets-Sheet l INVENTOR Karl, Bawmmnn ATTOR EY Oct. 17, 1933. K. BAUMANN STEAM GENERATING APPARATUS Filed Oct. 18 1930 2 Sheets-Sheet. 2

lNvEN-roR Karl. Baumann W AT TO R NEY Patented Oct. 17, 1933 UNITED STATES PATENT. lorrl'cefY 1,931,426. g STEAM GENERATING APPARATUS Karl Baumann, Urmston England "Application October '18, 1930, serial No.".489,658 and in GreatBritain November 1929 3 Claims. (Cl, 12 2533) -10 rectangular furnace chamber the walls of which are lined with water tubes, said chamber having an extension through which the furnace gases leaving the chamber pass, and having disposed in said extension, exposed to said furnace 1:15 gases, but substantially protected from the direct heat of the flame in the furnace chamber, a tube system constituting the heating portion of a closed circuit for the heat carrier, which circuit includes the heating tubes of an evaporator for the generation of steam. The steam generated in the evaporator preferably mixes with the steam generated in the water" walls of the furnace chamber and is passed through a superheater disposed in the said furnace extension before being 'used forpower generation or other purposes. p I The inventionis illustrated by way of example in Figs. 1, 2 and 3 of the accompanying drawings, which show diagrammatically two preferred forms ofsteam generating apparatus ac cording to the invention. i

Referring to the drawings, 1 is the furnace which may be adapted to be stoker fired, or fired with pulverulent or liquid fuel, and is enclosed by walls constituted of water tubes 2. These water tubes 2 are extended to line the extension of the furnace chamber and are connected to a suitable steam and water drum 3, hereinafter termed themain drum. Downcomers '2a pass externally from the main drum 3 to lower headers 4 at the bottom of the water walls to ensure proper circulation therethrough. The water tubes 2 forming the back of the furnace, are-bent at the upper part of the furnace chamber as shown at 5 to restrict somewhat the passage by which the furnace gases leave the chamber 1, the extension 6 of the chamber 1 taking the form of a substantially horizontal flue. The bent form of the water walls also serves to provide a screen for the tubes of the heat carrier 7 whichtubes arearranged so as to be heated by the furnace gases immediately upon their entry into the said extension.

The heat carrier, 7 comprises a heating element 8 disposed in an auxiliary drum 9 the i more superheater elements 11.

steam from which is led to a junction 10 i from. whence it-is passed, together, with the steam from the main drum 3, through oneor These superheater, elements arepreferably disposedto be heated by the furnace';-gases after passing some or all of the tubes of the heating system of the heat carrier 7. In Fig. 1 the superheater is disposed wholly beyond the' heating tubes of the heat carrier 7 and is arranged so, that the steam traversesthe first portion ,of, the superheater in the same general direction as the furnace gases, and the latter part of the superheater in counter-current to the furnace gases. In the constructions shown in Figs. 2 and 3 the super.- 10 heater element 11 is disposed between two porterial as shown by the cross-hatching. In suitable circumstances however such covering may be dispensed with. The gases'may finally pass to an economizer and air preheater as is usual.

A steam generator constructed as described J above will possess various advantages overknown constructions of generators of thekind referred to. The number of water tubes is reduced to the minimum required for lining the furnace walls, while the heating tube system of the heat carrier is exposed to a moderate heat OO only.' It will be understood that the heat carrier is preferably evaporated in the heating tube system and recondensed upon giving ,up heat in the tubes of the evaporator, from which it flows back to the heating tube system. The,95 latter moreover comprises tubes of relatively small diameter and, as well as the superheater, may be readily arranged in any manner that' may be convenient. j

In Figure 3 two superheaters are shown as connected alternately in series with the heating tubes 8 and 8', respectively, of two evaporators 9 and 9, as for example, in accordance with proposals made in my copending application for 1 Letters Patent eel-m1 No..4'73,695. It will read- 1 ily be, appreciated that, instead of providing the chamber having an extension through whichthe furnace gases leaving the chamber pass, a tube system disposed in said extension and constituting the heating portion of a closed circuit for a heat carrier which circuit includes the heating tubes of an evaporator for the generation of steam, and a superheater disposed in the said.

furnace chamber extension through which the steam generated in the walls of the furnace chamber and in the evaporator is passed before being used.

2. In a steam generating 'plant a substantiallyv rectangular furnace chamber the walls of which are lined with water tubes discharging at their upper ends into a steam and water-drum and connected at their lower ends by downcomers from said drum, said furnace chamber having an extension through, which the furnace gases leaving the chamber pass a tube system distion of a closed circuit which includes the heating tubes of an evaporator for the generation of steam, and a superheater disposed between said coils of the tube systemin the furnace chamber extension and connected at'one'end thereof to the steam outlet of the evaporator.-

3. A steam generating plant comprising a substantially rectangular furnace chamber the walls of which are lined with water tubes discharging at their upper ends into a steam and water drum and connected at theirlower ends by downcomers from said drum, said furnace chamber having an extension through which the furnace gases leaving the chamber pass and the walls of which are lined with Water tubes comprising prolongations of the furnace wall tubes, a'tube system disposed in said extension and containing a heat carrier, said tube system comprising two coils spaced apart and constituting the heating portion of a closed circuit which includes the heating tubes of an evaporator for the generation of steam and a superheater disposed between said coils of the tube system in the furnace chamber extension :and connected at one end thereof tothe steam outlet of the evaporator and also the steam outlet of a drum disposed in the water tube circuit.

KARL BAUMANN. 

